Kanellica, Angel of Bravery

Whenever Kanellica attacks, put a 3/3 angel token onto the battlefield tapped and attacking.
Whenever another angel enters the battlefield under your control, Kanellica gains +1/+1 until end of turn.
If a demon enters the battlefield under an opponent's control, you may sacrifice Kanellica. Destroy that demon. That demon's controller loses 1 life and you gain 1 life.